How Linux Distros Configure and Manage LVM

September 29, 2008 8:56 am

This is part 2 of a multi-part series on Linux logical volume management. If you are not already familiar with LVM, you may read part 1 here

We are huge fans of Linux logical volume management, and if you know just the basic benefits of using it, you will understand why. In spite of the benefits, most Linux desktop distributions, and a few server distributions, do not have support for it during installation. In this article, we take a look at those distros that support LVM and how they configure and manage it.
Compared to the number of active Linux distros, the list (of distros) that provide LVM as a configurable option during installation is short, very short. Bear in mind that some distros support LVM in their server editiion, but not in their desktop edition. Also, a few support it in their fee-based edition, but not in their community or free edition. Since this article is intended for those new to Linux, and to the concept of logical volume management, and who may not have the know-how to configure LVM via the CLI (Command LIne), the list below is of those Linux distros that have direct support for LVM in their graphical installers. Please note that aside from the LVM volumes, all the distros in the list set up a non-LVM boot partition:

CentOS, Fedora, Sabayon, and StartCom: LVM is the default disk partitioning scheme in these distributions, and all create two logical volumes – / and swap. Ext3 is the default / filesystem, and most of the available space is allocated to /.

Debian: No distro does LVM like Debian. Infact, no distro does disk partitioning like Debian. Although not the default, if you choose to, the Debian installer gives you the option to configure just two logical volume – / and swap, or to do a server-style partitioning, i.e., with separate logical volumes for /, /home. /var /tmp, and /usr. Most of the available space is allocated to /home. The option to configure LVM with encrypted volumes is also available

Foresight: LVM is not the default. If you elect to use LVM in Foresight, you will have to do it manually, using the gui.

Gentoo: Gentoo is a source-based distro, and there are no defaults. You can create any configuration you want with Gentoo

openSUSE: LVM is not the default partitioning scheme, but if selected, the installer will create three logical volumes – /home, /, and swap, with most of the available space allocated to /home. This is only slightly better than the default in CentOS, Fedora, Sabayon, and StartCom

Aside from Debian, none of the distros listed above provide a proper LVM configuration. Even Debian comes up a little bit shy of what is generally considered the proper way of setting up LVM. We”ll provide step-by-step instructions for configuring LVM in the another post, which will be the third part of this series on Linux logical volume management.

Managing LVM
Once configured, LVM can be managed from the CLI (Command LIne) by using the vg, pv, and lv series of commands. These are all very easy to understand and simple to use. In addition to the CLI commands, CentOS, Fedora, StartCom, and openSUSE have a graphical frontend for managing LVM. In openSUSE the gui client is part of the lvm2 package, which is installed by default. The gui client is accessible from Control Center -> System -> LVM

This is the main screen of openSUSE’s graphical LVM management utility.
Creating a logical volume with openSUSE’s LVM gui tool
Editing a logical volume in openSUSE

In Fedora and the Fedora-based distros with LVM support – CentOS and StartCom, there is a also a graphical utility for managing LVM. This utility, system-config-lvm, is more visually appealing and has a few more features than the openSUSE equivalent. Assuming it is not installed by default. you can installed system-config-lvm from the command line or by using the graphical package manager (see image below). A slideshow of screenshots of system-config-lvm is below the following image.

Main screen of the graphical utility for managing LVM under Fedora, CentOS, and StartCom. This tool has a “zoom-in” feature that openSUSE’s tool does not have.
Physical volume view of system-config-lvm
Logical volume view
Non-LVM partitions, typically the /boot partition are accessible the LVM graphical utility in Fedora, CentOS, and StartCom. In openSUSE’s LVM gui tool, non-LVM partitions are not accessible.

This ends the second part of the series on Linux logical volume management. To have subsequent posts in this series delivered automatically to your feed reader, you may subscribe to our RSS feed by clicking on the RSS icon atop the side bar.

2 Comments

i wanted to use lvm, but read some online articles that said file system journaling does not work with lvm. if this is true, what happens after a sudden power failure? i was worried about data loss and did not try it.